Consolidated Balance Sheet Parentheticals (Parentheticals) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Fixed maturities securities at amortized cost	$ 38,361	$ 37,253
Equity securities at cost	106	191
Allowance for uncollectible reinsurance receivables	37	38
Allowance for uncollectible insurance receivables	46	51
Accumulated depreciation on property and equipment	254	382
Due to Related Parties	$ 50	$ 82
Common stock, par value	$ 2.50	$ 2.50
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	273,040,243	273,040,243
Common stock, shares outstanding	270,495,998	270,274,361
Treasury stock, shares	2,544,245	2,765,882